CK-12 Foundation
ASA and AAS Triangle Congruence Lesson
The location of the side makes a difference. One of the videos in a geometry playlist introduces angle-side-angle and angle-angle-side congruence relationships. Using drawings, the video shows how these two congruence statements are...
CK-12 Foundation
SSS Triangle Congruence: Lesson
Gimme three sides, mister! The video introduces the Side-Side-Side Triangle Congruence Theorem. Using segments of different lengths, the portion of a larger playlist on geometry shows that only one triangle can be built.
CK-12 Foundation
The Third Angle Theorem: Lesson
If two sets of angles are equal, the third set is too. An informative portion of a playlist on geometry develops the Third Angle Theorem for triangles. Using the theorem, the presenter shows how to determine the measure of missing angles...
CK-12 Foundation
SAS Triangle Congruence: Lesson
SAS is not just a spy organization. A section of an extensive geometry playlist introduces a way to show two triangles are congruent, SAS. Using diagrams, the video provides an explanation by showing only one triangle is formed with two...
CK-12 Foundation
Creating Congruence Statements: Lesson
Provide a large amount of information in a short statement. A segment of a playlist on basic geometry introduces the notation to denote congruence between two figures. The video shows how to read corresponding parts from a congruence...
CK-12 Foundation
Congruent Triangles: Lesson
Given two congruent triangles, the resource provides the definition of congruent triangles and marks the corresponding parts. The portion of a basic geometry playlist shows the triangles are congruent by moving one on top of the other...
CK-12 Foundation
Congruent Angles and Bisectors: Lesson
How is congruence shown? Using angles, the resource introduces the congruence symbol and explains the meaning of being congruent. A segment of a larger playlist on basic geometry discusses bisection as a way to arrive at two congruent...
CK-12 Foundation
Properties of Equality and Congruence: Lesson
What properties of equality also work for congruence? Part of basic geometry playlist, the video relates algebraic properties to their counterparts of congruence. Learners see how the properties mean the same whether with equality or...
Curated OER
How Do You Find a Scale Factor in Similar Figures?
Three angles of one triangle are equal to the corresponding angles in another triangle. Use a ratio of corresponding sides to find the scale factor. Actually, there are two scale factor values. The instructor will explain how to get both...
Curated OER
What are Perpendicular Lines?
Perpendicular lines intersect to form right angles - four of them to be exact. Vertical angles, congruent angles, 90 degrees each, these are some of the special properties of perpendicular lines. Watch this video to find out a couple...
Curated OER
How Do You Find a Value for x that Makes Two Lines Parallel?
So you have a transversal line intersecting two parallel lines and you are looking for a value that would make two corresponding angles congruent. You have all the information needed to write an equation to find the value. So write that...
Curated OER
What Does Congruent Mean?
Two figures are congruent if they have the same size and shape. Line segments can also be congruent if they are of the same length. Vertical angles created by intersecting lines are always congruent. Polygons that have matching angles...
Curated OER
How Do You Find a Scale Factor in Similar Figures?
Three angles of one triangle are equal to the corresponding angles in another triangle. Use a ratio of corresponding sides to find the scale factor. Actually, there are two scale factor values. The instructor will explain how to get both...
Curated OER
How Do You Find a Value for x that Makes Two Lines Parallel?
So you have a transversal line intersecting two parallel lines and you are looking for a value that would make two corresponding angles congruent. You have all the information needed to write an equation to find the value. So write that...
Curated OER
What are Vertical Angles?
What makes vertical angles so special? Here's a few words that might help you figure out why: intersecting lines, congruent angles, opposite, supplementary angles. Still wondering? Then watch this video for a good explanation of vertical...
Curated OER
What are Similar Figures?
Similar figures have the same shape, the same corresponding angles, but different lengths of their corresponding sides. The teacher explains just what all that means. She demonstrates how to compare the two shapes to prove they are similar.
Khan Academy
MTEL Math Practice Test: 36-40
Sal goes into detail when solving these problems on the practice MTEL math test, especially the complicated details of question 36. Viewers will rest assured of the ease with which Sal addresses these increasingly tricky problems.
Curated OER
How Do You Find Missing Measurements of Similar Figures Using a Scale Factor?
Similar figures have corresponding sides and corresponding angles. With this in mind, missing values can be found by using a scale factor. Not sure how to do that? Watch this video as the instructor illustrates how to set up the known...
Curated OER
What are Equilateral, Isosceles, and Scalene Triangles?
Triangles are classified by their angle measurement as well as by the length of their sides. Here are some names that identify the types of triangles: right, isosceles, equilateral, scalene, obtuse, and acute. Watch this video to learn...
Curated OER
How Do You Find Missing Angles in a Transversal Diagram?
Parallel lines with a transversal and one given value, find the value of the other seven angles. There are many geometric terms about angles and lines to know the meaning of and understand their relationship to each other. Understanding...
Curated OER
What are Vertical Angles?
What makes vertical angles so special? Here's a few words that might help you figure out why: intersecting lines, congruent angles, opposite, supplementary angles. Still wondering? Then watch this video for a good explanation of vertical...
Curated OER
What Does Congruent Mean?
Two figures are congruent if they have the same size and shape. Line segments can also be congruent if they are of the same length. Vertical angles created by intersecting lines are always congruent. Polygons that have matching angles...
Curated OER
What is a Rhombus?
A closed figure with four sides means it's a quadrilateral. Each of the different types of quadrilaterals have special properties. The instructor in this video explains the special properties of a rhombus. Parallel sides and congruent...
Curated OER
What is a Regular Polygon?
What makes a polygon a regular polygon? Does this mean there are irregular polygons? For a polygon to be classified as a regular polygon, all the sides must be congruent and all the angles must be congruent. Those are the two rules that...